In my U.S. Pat. No. 3,875,642 there is disclosed a seaming apparatus utilizing three sets of rollers that is particularly suited for forming continuous seam structure along the side edges of panels having vertical sidewall portions arranged parallel to one another and side connecting flanges that extend laterally out from the upper edge of vertical sidewall portions.
Maxfield U.S. Pat. No. 2,160,336 discloses non-reversible seaming apparatus wherein the movable rollers are not on a common base and the axes of the rollers do not remain parallel during movement.
Parham U.S. Pat. No. 3,015,293 discloses a non-reversible seaming apparatus wherein only a single rod through the center of the block is used to support the base portions for guided movement and the rollers do not embrace at least a side section and corner of an outer inverted channel to facilitate tracking in the channel.
Thompson U.S. Pat. No. 3,771,482 discloses a non-reversible seaming apparatus wherein separate bases are used for the movable rollers and more than two sets of rollers are required to form the seam.
The seaming apparatus of the present invention provides another approach to seaming panels and has been found to be particularly suited for forming continuous seam structure in adjacent panels that have inclined sidewall portions and raised side edge portions. These panels are disclosed in more detail in a copending application of the same inventor entitled "Wide Panel, Panel Assembly, and Panel Forming Apparatus," Ser. No. 236,832.